The chairman and largest investor in Sears Holdings is offering to buy the retailer out of bankruptcy — including 500 of its remaining stores — in what may amount to the chain's last hope to survive its precipitous decline.

"Sears is an iconic fixture in American retail and we continue to believe in the company’s immense potential to evolve and operate profitably as a going concern with a new capitalization and organizational structure," Lampert said in a letter.

"Our proposed business plan envisages significant strategic initiatives and investments in a rightsized network of large format and small retail stores, digital assets and interdependent operating businesses."

Lampert said the acquisition would keep 50,000 Sears employees working.

He said the deal would include 500 stores, which covers essentially all of the locations Sears has not identified for closure. The deal would include Sears and Kmart stores.

It would also include the Kenmore appliance and DieHard tool brands, key real estate and the company's inventory and receivables.

Lampert described his offer as worth about $4.6 billion "in total consideration." He said the price would include debt to be issued by Sears, "a credit bid" of about $1.8 billion and the assumption of certain liabilities.

A Sears spokesman declined to comment on the offer.

In recent years, Lampert's hedge fund, ESL Investments, has loaned Sears more than $2.4 billion in financing. So he could lose a fortune if Sears is forced to liquidate or sticks creditors with steep losses.

But critics have also accused him of structuring his deals to ensure he gains access to key assets in the event of the retailer's demise. He was also earning hundreds of millions annually in Sears debt payments before the retailer's bankruptcy.

A committee organized to represent Sears' unsecured creditors in the case filed a motion accusing ESL of potentially structuring deals to benefit itself. ESL, which is wholly owned by Lampert, has denied those accusations, saying it should be credited for propping up Sears in recent years.

In his letter proposing the deal, dated Wednesday, Lampert also noted that his bid was conditioned on releasing ESL "from any liability related to any" deals that the hedge fund engineered before the bankruptcy.

In one key deal that's under scrutiny, Lampert helped engineer a spinoff of 235 of the most valuable Sears properties to a real estate investment trust called Seritage Growth Properties. That 2015 deal generated $2.7 billion for Sears.

As of Sept. 30, Seritage still had 102 Sears leases, covering 12.4 million square feet and $61.2 million in annual base rent.

Since August, the retailer has closed or announced plans to close about 228 stores. That's on top of thousands of closures since the company's peak earlier this century.

Sears has suffered from the rise of Amazon, powerful retailers like Walmart and Target, a lack of investment in its stores, and legacy costs, including pensions.

The company filed for Chapter 11 bankruptcy protection on Oct. 15, hoping to use the restructuring process to shed debt, escape expensive leases and reemerge as a viable company